Groundwater management system

Abstract

The invention relates to a method of managing ground water resources, where bores are used to extract ground water such as for agricultural, mining and town water supply purposes. It involves a method for managing a groundwater resource including, providing at least one production bore that is adapted to extract groundwater from an aquifer, providing at least one monitoring bore that provides a measure of the extraction capability of removing water from the aquifer, measuring the hydraulic head of groundwater in the aquifer by means of the monitoring bore, and monitoring at least one indicator of the capability of extracting groundwater from the bores. The method involves determining at least one trigger point at which further monitoring of, or action in respect of, the groundwater extraction is to be undertaken, and intervening when this trigger point is reached during groundwater extraction. Preferably there are at least two trigger points; one to trigger a review and another that triggers management action.

The invention claimed is:  
     
       1. A method for extracting water from a groundwater resource, the method comprising:
 (a) providing a production bore adapted to extract groundwater from a groundwater resource; 
 (b) providing a monitoring bore adapted to monitor the groundwater resource; 
 (c) providing a production data logger associated with the production bore, the production data logger adapted to measure a flow rate of groundwater from the groundwater resource; 
 (d) providing a monitoring data logger in the monitoring bore, the monitoring data logger adapted to measure a hydraulic head of water in the monitoring bore; 
 (e) providing a programmed system adapted to receive data from the production data logger and the monitoring data logger; 
 (f) receiving data into the programmed system relating to the hydraulic head of water in the monitoring bore, the hydraulic head of water in the monitoring bore being an indicator of the capability of extracting groundwater from the production bore, 
 (g) computing probability distributions of hydraulic head of groundwater for the production bore using the programmed system; 
 (h) constructing a programmed model of the groundwater resource to compute probability distributions of water drawdowns from the groundwater resource; 
 (i) computing hydraulic head trigger points by the programmed system for further water extraction action, the trigger points are: 
 (1) a review trigger point (T RV ), being
     T   RV   =h   p1   −dd   p1avg    
 wherein
 h p1 =head at a probability of between 50% and 80%; and 
 dd p1avg =drawdown at probability of between 50% and 80%; 
 
 
 (2) a response trigger point (T RP ), being
     T   RP   =h   p2   −dd   p2avg    
 wherein
 h p2 =head at a probability of between 80% and 99%; and 
 dd p2avg =drawdown at probability of between 80% and 99%; 
 
 
 wherein
 when the programmed system receives data from the data loggers that causes it to compute a trigger point T RV , the programmed system initiates a higher frequency of data sampling in the production bore, in the monitoring bore or in both the production bore and monitoring bore; and 
 when the programmed system receives data that causes it to compute a trigger point T RP , the programmed system instructs a groundwater extraction rate change by the production bore; and 
 
 (j) changing the extraction rate from the production bore. 
 
     
     
       2. The method of  claim 1  wherein
 h p1 =head at a probability of about 68%; 
 dd p1avg =drawdown at probability of about 68%; 
 h p2 =head at a probability of about 90%; and 
 dd p2avg =drawdown at probability of 90%. 
 
     
     
       3. The method of  claim 1  having a plurality of monitoring bores. 
     
     
       4. The method of  claim 2  having a plurality of monitoring bores. 
     
     
       5. The method of  claim 1 , wherein constructing the programmed model comprises a step of receiving data from a rainfall sensor. 
     
     
       6. The method of  claim 1 , wherein constructing the programmed model comprises a step of receiving data from an evapotranspiration sensor. 
     
     
       7. The method of  claim 1 , wherein constructing the programmed model comprises a step of receiving data from a salinity sensor. 
     
     
       8. The method of  claim 1 , comprising providing further monitoring bores having further monitoring data loggers and receiving data from the further monitoring data loggers when the Review trigger point T RV  is reached. 
     
     
       9. The method of  claim 1 , wherein when the response trigger point (T RP ) is reached, the programmed system reduces or ceases extraction of ground water from the groundwater resource, or increases the groundwater resource recharge. 
     
     
       10. The method of  claim 1  including the step of computing with the programmed system, one or more sustainability bands to provide an early warning of the onset of stress on the groundwater resource such that when the response trigger point (T RP ) and a lower sustainability band cross, the programmed system instructs the reduction of pumping from the production bore.